The present invention pertains to data transmission between switching offices and more particularly to an arrangement for Common Channel Interoffice Signaling for use in a switching system.
Common Channel Interoffice Signaling (CCIS) is a relatively new signaling arrangement in which signaling and supervisory data, usually sent by the voice trunks, is transmitted via data links between switching offices. Previous telephone switching systems implemented the CCIS feature through the use of CCIS data links directly operated by the common control processor of the switching office.
CCIS is a relatively new telephony feature which has a broad range of potential uses. The CCIS feature is constantly being redefined and enhanced. It is expected that other uses of this feature will be found for many years to come.
In the traditional arrangement of the CCIS system discussed above, any change made to the CCIS feature severely impacted the program of the switching office's common control processor. Such modifications are costly in terms of reprogramming costs.
Accordingly, it is the object of the present invention to provide a CCIS system for use in a switching office while permitting feature changes and modifications to the CCIS system with minimal impact on the switching office.